Internal-combustion engine.



PATENTED AUG. 4, 1908.

O.KELLY.

INTERNAL COMBUSTIN ENGINE. 1

rmm mmm un. 19,;901.

APPLICA "Ws 1K xx oRIN KnIiLLoFwEtts'Tox, oni-o Y mTEnNnLoom-Bns'rron To all whom it may cof/wem:

Be it known th et I, ORIN KELLY, a citizen of the United States, residing et Wellstomin the count-y of Jackson and Stute of Ohio, have invented a new and useful Internal- Comoustion Engine, of which thefollowing is a specitication.

This invention relates to internal combustion engines, and has for its principelobject to provide en engine in whlch the adventeges of both the two cycle and four cycle ty es of engines are combined.

llt is n well known fact to those familier with internal combustion engines, that the two cycle type of engine is, mechanically considered, fer superior to the four cycle type, because of its greater simplicity and fewer working parts, and chieily because the explosion or impulse is given. every revolution as against en impulse every two revolutions in the four cycle type of engine, but on account of the feet that it has not been hit erto possible to sufliciently clear the cylinder of the dead gases of a. previous explosion before the charge for the next impulse, the two cycle engine has n tendency to choke up and otherwise not work eicicntly except et low speeds.

In constructing en engine in accordance with the present invention, provision is mede for the employment of en additional scavenging piston, oy which the waste products of combustion are forced from the cylinder without' interfering with the introduction of the fresh charge.

With this and other objects in view, as Will .more fully hereinafter e ipear, the invention consists n1 certain nove features of construction end errnngement of parte, hereinafter fully described, illustrated in the accompanying drewing, and particularly pointed out in the appended claims, it being understood that various changes in the-form, proportions, size and minor details of the structure may be :node without departing from the s irrt or secriiicing eny ob the edvsntages c the invention.

In the `iccornpfgtnying drewingsz-Figure 1 is a sectional elevation of an engine provided with a. scavenging piston constructed in accordance with the invention, the nxuin piston being shovm near the completion of the .vorking stroke. Fig. 2 is e similar vie v of the cy indcr and istons showing the position ns- .sinned by t e pistons near the com letion of the compression stroke. Fig. 3 is a cliateil per- Specication o! Lettere Petent. `Application led Ap1il 19, 1907. Seri No. 369.139. i l

cation.

' the bottom :in annular. ri

UNITED STATES onnrcn. -rrr- '.-Ef l r'atenred Aug. 4,19`os.

spective view looking toward the under side of the scavenging iston. Fig. 4 is c view similar to Fig. 2, il ustreting e. slight modifin Similar numdrels of reference are employed to indicate corresponding parts throughout the several figures of the drawings. A

The crank ease l10 is provided with bearings for ashnft 11carrying a. crank 12 that 65 is connected by a rod 13 to e piston 14 of the ordinary construction, and seid piston is arranged to travel within a cylinder 15 provided with c water jacket or other cooling men-ns ol the usuel type.\

Lending into the crank case is e velved in .let 16,:1nd from the top of the cylinder leeds a vnlved exhaust 17. The charge ndinitted ,Y

to the crank case is partly compressed on the working stroke of the piston und passes through the transfer ports 18 to the upper side of the piston at the completion of the .working stroke.

Arranged within the cylinder is a scavenger piston 20, seid piston being provided with suitable pecking rinffs21 und having at 22 und a cent1-nl lug 23, which ride :ige-inst the top of the piston proper curing the working stroke. The rib 22 is provided with numerous passages 24 in order to permit the entrance of the fresh charge between the two iistons.

At the explosion cham er end of the cy inder are arranged e number of cushions 27 which may oe formed of osbestosor other slightly yieldeble meterla-l in order to prevent noise when the scev enver piston strikes y age-inst the head. The wall of the cylinder is provided with n number` of smell b'yiss ports 29, of greater height than the widtof the piston 20so that the fresh charge may pass from the lower to the upper side of said piston 20 in readiness for the next worki ng stroke.

It will be noted that the exhaust ort 17 is so arranged with reference to the y-pass ports and piston that the piston will close the exhaust port before opening the by-pass ioo ports, so that :my escape of the fresh charge s eech other i order to prevent any tilting or jamming of the scavenger piston through excess pressure at any point. The orilla-ust port is open, andthe roducts of combustion will flow from the cy inder through snide):- haust port, thereby reducing the pressure at the explosion'chamber end of the cylinder, and when this occurs the -gases confined bctvreen the two pistons will immediately start to move the piston Z0 upward and the latter will travel toward the explosion chamber end ofthe cylinder,sweeping all of the burned gases from the cylinder;- This movement is assisted by the pressure of the fresh charge which enters above the piston 14 as soon as the latter is moved-slightly further 'down from the position shown in Fig. 1,so that tl@a complete upward travel of the scavenger piston will be insured. As the scavenging 'p1ston nears the limit of its upward movement, it will close the exhaust port 14 and this will open the by--pass 29 of which there may be any desired number, and by this time the main piston is approachin the limit ci compression movement, and t e gas compressed in advance of said piston will be forced through the by-pass ports to the space between the top of the scavenging usten, and he head of the explosion chamrer, whereupon another explosion takes place, and the operation is repeated asbcEOrc.

While it is preferred to operate the scav' enging piston'by pressure of ases and thus avoid outside connections', t c scavenging piston may be provided with a rod 3 4 extending through the head of the explosion chamber,l as shown in Fig. 4, said rod being o er ated in any suitable manner to accomp ish the desired result. One mechanism is illustrated in Fig.- 4 and consists of a. spring arranged between thehead of the explosion4 member and a Flange or collar 35 at the head 'of the rod. When the scavenging piston moves down under the force of the working stroke, the s ring is placed under stress, and when the'- ex aust valve is open, the spring will expand and `will move the scavenging piston upward and force thc exploded charge out of the cylinder. It will be seen that all of the functions of supply, compression, eX

pansionand exhaust are as thoroughly and completely accomplished and the dead gases are as thoroughly swept from the' cylinder and the wasting of live gases as cffectually prevented as in any engine of four cycle design, while the simplicity of design and frequency of impulse of the two cycle engine are retained.

The construction shown in Fig. 4 1s such l that the charge may be taken m as 1n the ordinary four cycle type o-cngine, thus avoiding the necessity of initial compression of the charge in the cra-nk case. It is obvious that the returning device for the scavenging piston, which in the present'instancc is shown in. the -form ot a spring, may be sufficiently powerful to elTeeta complete return of 'the scavenging piston without theaid of the pressure from thc charge and may move in the same manner as the ordinary )istn of a -our cycle engine moves during t e suction stroke. While the spring has been illusl trated as one means oi securing this result, it is obvious that any`othersuitable mechanical connections may be employed for the same purpose.

In an internal combustion engine, a cylinder, a piston, a scavenging piston, an inlet portyfor directing the explosive charge between thc two pistons, a by-pass ort 1n the cylinder and u'nder the control o 'the scavenging piston, and an exhaust port also under the control of said scavenging piston and arranged to be closed before the by pass port is opened.

In testimony that I claim the foregoing as my own, I have hereto aliixed my signature in the presence oftwo witnesses. y

= GRIN KELLY.

Witnesses:

EDWARD R. KELLY,

T. A. MGFARLAND. 

